1. Field of the Invention
The present invention relates to catalytic material for promoting growth of carbon and its preparing method, and electron emitting device, electron source, image forming apparatus, secondary battery and body for storing hydrogen using a carbon fiber formed by the catalytic material. The image forming apparatus of the present invention can be used as an image forming apparatus for an optical printer having a photosensitive drum as well as a display device for television broadcasting, an image display device of television conference system or computer and so on.
2. Related Background Art
A method of making carbon fibril is disclosed in Japanese Patent Laid-Open Gazette No. 4-504445 (corresponding family patents WO9007023 and EP0451208). Further, a method of preparing filamentary carbon is disclosed in Japanese Patent Laid-Open No. 3-260119 (corresponding family patents U.S. Pat. No. 4,900,483 and EP433507).
Further, a method of preparing carbon nanotube is disclosed in Japan Patent Laid-Open No. 2000-95509.
An electron emitting element using carbon fiber is disclosed in U.S. Pat. No. 4,728,851 publication, U.S. Pat. No. 5,872,422 specification, U.S. Pat. No. 5,726,524 specification, Japanese Patent Laid-Open No. 8-115652, Japanese Patent Laid-Open No. 2000-057934, Japanese Patent Laid-Open No. 2000-208028, Japanese Patent Laid-Open No. 2001-052598, “Carbon Nanotube FED with Graphite Nano-Fiber Emitters” SID2000, pp398-401, “A nanotube-based field emission flat panel display” Applied Physics Letters, vol. 72, No. 22, pp2912-2913 (1998) and so on.
And, results of Raman spectrum analysis of carbon fiber is disclosed in Chemical Physics Letters 340 (2001), pp 413-418, as an example, as shown in FIGS. 13A and 13B.